The present invention relates to a compressor for vehicle comprising a compression portion driven by rotating a rotary shaft.
One kind of the compressor for vehicle is a scroll compressor, for example. The scroll compressor has a fixed scroll and a movable scroll. The fixed scroll and the movable scroll mesh each other. In the compressor, one end of the rotary shaft is connected to the movable scroll. In the compression portion, by turning the rotary shaft, refrigerant is compressed by rotating the movable scroll around the fixed scroll. In addition, both end portions of the rotary shaft are rotatably supported by a bearing in the housing.
In case of such the scroll compressors, when a stress in the compression portion, for example compression reaction force, occurs in the rotary shaft direction, a vibration is transferred along the rotary shaft direction. If the vibration is in resonance with a vehicle side vibration, the produced noise becomes bigger. The Japanese Unexamined Patent Application Publication No. 3-149381 discloses a technology to reduce the noise. In FIG. 4, a main bearing (not shown) is supported in a main bearing member (not shown) formed in a closed container 90 (housing). A sub bearing 92 is supported in a sub bearing portion 91. One end portion of a main shaft (not shown) in a crankshaft 93 (rotary shaft) is rotatably supported, and the other end portion of the main shaft is rotatably supported by the sub bearing 92. The crankshaft 93 is integrally rotatably connected to a rotor 94 of a motor.
Additionally, the other portion of the crankshaft 93 is formed slimmer than a connection portion connected to the rotor 94. A stepped portion 93A is formed in the crankshaft 93 with a different diameter of the crankshaft 93. A wave-shaped washer 95 is located between the stepped portion 93A and the end face of an inner race 92A of the sub bearing 92.
By the wave-shaped washer 95, an elastic force is provided toward the direction of the crankshaft 93. The elastic force of the wave-shaped washer 95 performs as a preload to the inner race 92A. Therefore, the vibration of the crankshaft 93 is reduced by the preload of the wave-shaped washer 95. As a result, a noise caused by resonance is reduced.
However, the Japanese Unexamined Patent Application Publication No. 3-149381 leaves room for a further improvement to reduce common vibrations by reducing the vibration of the crankshaft 93 by the wave-shaped washer 95.
The compressor for vehicle of the invention provides a feature by which the vibration toward the direction of the rotary shaft is suppressed and vibration in accordance with the vehicle side vibration source is controllable to reduce resonance.